I have been looking for this for a looong time.
Jon Galloway writes about two sites created by Dan Vine that allow you to enter an URL and it will display a screenshot of the website as rendered by IE7 or Safari. This is extremely useful for testing out web designs on alternate platform. Much cheaper than buying a Mac to test your work on Safari browsers.
I also want to commend Dan for such clean design. Each site is like a well written function. It does one thing and it does it well. A joy to use really.
One thing to note, iCapture produces a screenshot of the entire page, potentially producing a tall image. At the time of this writing, ieCapture takes a screenshot of the actual browser window, which doesn’t show the entire document.